1. Technical Field
This invention relates to an automatic air intake temperature regulator apparatus and method for regulating the temperature of air entering an engine by varying the amounts of ambient and preheated air entering the engine.
2. Description of Prior Art
The air entering an internal combustion engine is often preheated to improve engine performance and eliminate carburetor icing when operating the engine in cold ambients. To further improve engine performance, it is sometimes necessary to regulate the temperature of the air entering the engine as the ambient conditions change. One common method of regulating temperature is to regulate amounts of ambient air and preheated air entering the engine.
Some prior regulator devices which regulate the air intake temperature are manually controlled. For example, such regulator devices have been used on generator sets which provide an auxiliary power source in numerous applications such as recreational vehicles, ambulances, etc. One problem with such regulator devices is that there is often a two position switch controlling the amounts of preheated air and ambient air entering the engine. The switch must be manually moved as the temperature of the ambient air changes. Failure to properly move the switch can cause problems affecting engine performance. If the air entering the engine is too cold, the throttle plate may freeze into position (carburetor icing) and the fuel may not likely mix properly with the air. If the air entering the engine is too hot, the engine may lose power.
Other regulator devices automatically regulate the temperature of air entering the engine. In these devices, a shutter may be employed to automatically regulate the amounts of ambient and preheated air which enters the engine. The temperature may further be regulated by mixing varying amounts of ambient air with preheated air with a variably positionable shutter. In some prior devices, the shutter is positioned by a temperature sensing device mounted such that it measures the downstream temperature of the mixed air entering the engine. One problem encountered with these types of devices is that it is difficult to mount the temperature sensing device in the downstream airflow and it may require a complex linkage connecting the temperature sensing device back to the shutter. Furthermore, the air in the downstream air flow includes a moving mixture of ambient air and preheated air. Care must be taken to assure that the temperature sensing device accurately measures the temperature of t e air in this mixed, moving state. Examples of prior art regulator devices can be found in U.S. Pat. Nos. 4,632,084; 4,565,176; and 4,526,156.
It is clear that there has long existed an unfilled need in the prior art for an air intake temperature regulator that automatically and variably regulates temperature, and further permits easy mounting of the temperature sensing device and allows accurate sensing of temperature to more easily regulate the temperature of the air entering the engine. The present invention solves these and other problems associated with the prior art.